Astronomers find a giant new galaxy concealed within a puzzling region of the Milk Way

Astronomers have found a giant "extragalactic structure" concealed behind the Milky Way, according to a new study published in Arxiv.

The discovery of the structure, which appears to be a colossal galaxy cluster, contributes to filling in this mysterious region of our cosmic map, known as the "zone of avoidance." Nobody has known what exists in this region which obscures 10 to 20 percent of the sky- until now.

Tapping into the power of near-infrared (NIR) wavelengths using the VISTA telescope

The study explained that the zone of avoidance (ZOA) does not allow clear optical observations of extragalactic sources behind the Milky Way. The research paper describes the reason for this being an "extinction of the optical emission of these objects." This means that most extraterrestrial structures within the ZOA are hidden, or unobservable.

In light of this, researchers of the new study decided to carry out their observations using near-infrared (NIR) wavelengths. They argue that NIR could be a source of astronomical findings, including discovering new galaxies. NIR's success in this could help to complete the picture of the enormous structure in this still "little-explored" region of space.

And they may have a point, judging by their discovery of what could be a viable structure. 

Hello, galaxy cluster 'VVVGCl-B J181435-381432' - thanks to the VISTA telescope

"A new galaxy cluster, VVVGCl-B J181435-381432, behind the Milky Way bulge," which helps to complete "the picture of the large scale structure in this still little explored area of the sky," outlined Daniela Galdeano on the 'context' section of the study, Galdeano is an astronomer at the National University of San Juan in Argentina and one of the study's lead authors (yet to peer-reviewed).

Galdeano and colleagues were able to locate the new cluster within the ZOA, thanks to the VISTA telescope. VISTA, located in Paranal, Chile, stands for the European Southern Observatory's Visible and Infrared Survey Telescope for Astronomy and is part of the VVV Survey. The latter is a project that examines the Milky Way bulge at infrared wavelengths.

The success of the observation using VISTA relates to the fact that longer wavelengths of light, such as those in the infrared band, can pass through the Milky Way's haze and reach telescopes on Earth. In contrast, the galactic plane effectively shuts out practically all visible light in the zone.

ZOA is also home to the so-called 'Great Attractor,' an unknown gravitational anomaly

The so-called Great Attractor, an unknown gravitational anomaly pulling galaxies and clusters toward it, is present in the ZOA and hidden galaxy clusters. The only way to understand the nature of this massive attractor is through additional observations and investigation.

Still, the researchers explained that due to the high star density and line of sight obscuration caused by dust, it is challenging to detect galaxies behind the galactic plane.

The team is "prepared to be surprised" by the ZOA's future revelations

"We suspected the presence of structure," he added, "but since this was a 'blind region' before, this discovery of a new galaxy cluster was a nice confirmation," said Dante Minniti, director of the Institute of Astrophysics at Andrés Bello National University in Chile and a co-author of the study, in an email to Vice (Motherhood).

He further remarked that the team is "prepared to be surprised" towards any future findings of the mysterious zone.

The finding of this galaxy cluster provides an intriguing window into the Milky Way's interior. Suppose researchers preserve in their research within the ZOA. In that case, we might be able to fully comprehend what truly lies there. And on that note, may the force be with them. 

The complete study can be found here, and as mentioned earlier, is yet to be peer-reviewed.